Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true, so safety is covered, but the description adds real value beyond that: the cost behavior (FREE, polling never costs) and the state machine plus the fact that a completed task yields the brief markdown and sources. No output schema exists, so disclosing the return payload here is a genuine contribution.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two tight sentences with zero filler; the cost note and the return-state list are front-loaded, and every clause carries information an agent needs.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a single-parameter polling tool with no output schema, the description covers what it does, its cost, and what it returns, which is nearly everything needed. Minor gaps remain around polling cadence and terminal-state handling, but the agent can call it correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%; the task_id parameter is fully documented in the schema, including a concrete example and its provenance from request_brief. The description adds no further parameter semantics, so the baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource: "Check the status of a custom brief task," and enumerates the returned states (queued/working/done/failed). It ties to the sibling request_brief via the task_id reference, though it never explicitly distinguishes itself from get_brief.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

"polling never costs" strongly implies this is the polling tool and is safe to call repeatedly, which is useful usage context. However, it never states when to use this versus get_brief, nor when to stop polling (e.g., once done/failed), leaving the workflow to inference.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.